HSD Sound Systems · Subwoofer

HSD Battlehawk

Name: HSD Sound Systems Battlehawk
Brand: HSD Sound Systems
SKU: 21FLH28
Price: 7500.00 USD
Availability: InStock

Model 21FLH28

The BattleAxe evolved, flatter response, more power, more clarity.

The Battlehawk redefines what's possible in front-loaded horn subwoofers. Building on the legacy of the world-renowned BattleAxe 21" FLH, HSD engineered a flatter frequency response, exceptional clarity, and significantly higher power handling, 3,000 W continuous at 108 dB sensitivity. Built for touring, large-format events, and custom projects. Hand-built by Hennessey Sound Design in Massachusetts, and backed by a 5-year limited warranty.

$7,500 retail

Built to order. Quote includes freight, system design, and current lead time.

Request Quote Call 210.489.0492

Most quotes sent same business day. Real people, no scripts.

HSD Sound Systems Battlehawk subwoofer by Hennessey Sound Design

Amplification

Passive cabinet, amplification required

The Battlehawk presents 6 ohms nominal and handles 3,000 W continuous. Plan one channel of a KD Series 4-14KD (3,500 W into 4 ohms) per cabinet, four Battlehawks per amp.

1 amp channelper cabinet, 6Ω nominal

Driver

1×21″front-loaded horn

Response

28Hzto 150 Hz (-3 dB); 25 Hz at -10 dB

Power

3,000Wcontinuous (6,000 W program)

Sensitivity

108 dB1W/1m

Full specifications

HSD Battlehawk (21FLH28) specs

Factory specifications from Hennessey Sound Design. Download the cut sheet for drawings and driver details.

Frequency Response	28 Hz - 150 Hz (-3 dB); 25 Hz - 250 Hz (-10 dB)
Sensitivity	108 dB (1W/1m)
Drivers	1 x 21" (front-loaded horn)
Power Handling	3,000 W continuous (6,000 W program)
Impedance	6 ohms nominal
Dimensions	30" W x 60" H x 48" D
Weight	340 lbs
Connectors	2 x NL4

HSD Battlehawk cut sheet (PDF)

Why buy from Fullblast

An HSD system is a build, not a box. We manage the whole thing.

Authorized HSD dealer

Fullblast Sound is one of only three authorized HSD Sound Systems dealers in the United States. Factory pricing, factory support, and a direct line to the Massachusetts shop on every order.

Real dealer support

We spec the system against your room and application, handle freight and logistics, and stay on call after delivery. Talk to us before you order and we will get the design right the first time.

Nationwide freight

Every HSD cabinet ships crated freight from the factory. We quote and coordinate delivery to your dock or venue anywhere in the country as part of the system price.

Financing available

Spread an HSD system across payments instead of a single check. See financing options or ask for terms with your quote.

Get a real quote

Send a system spec, not a price shopping number

Tell us the room, the audience size, and what you run today. We come back with the right HSD build, amplification, freight, and current factory lead time. One short form.

Request Quote Or call 210.489.0492

Same business day response.

Buyer research

Questions buyers ask about the Battlehawk

Common pre-purchase questions on the HSD Battlehawk.

What did HSD change from the BattleAxe?

Three things: response, power, and clarity. Building on the world-renowned BattleAxe 21″ FLH, the Battlehawk delivers a flatter frequency response through its passband, raises continuous handling from 2,500 to 3,000 W, and adds a point of sensitivity (108 dB). It is the same weapon, re-forged for touring and large-format events.

What amplifier drives the Battlehawk?

3,000 W continuous (6,000 W program) at 6 ohms nominal. One channel of the HSD KD Series 4-14KD (3,500 W per channel into 4 ohms) per cabinet is the natural pairing, a single 2U amp drives four Battlehawks with FIR presets and per-channel RMS/peak limiting.

How big is it in the truck?

Plan for it: 30″ W × 60″ H × 48″ D and 340 lbs per cabinet. That is festival-scale hardware, the payoff is festival-scale output. If truck space and crew are the constraint, look at the 250 lb Tomahawk instead.

Battlehawk or BattleAxe, is the upgrade worth $400?

If you are buying new and chasing maximum output and the flattest low end, yes: 500 W more handling, 1 dB more sensitivity, and a flatter curve for $7,500 vs $7,100. The BattleAxe remains in the line because its 4/8-ohm driver options and long track record fit some fleets better. We are happy to talk through both against your amp rack.

System design